Mono- and multi-functional acrylamides are important olefinically-unsaturated polymerizable monomers in photo-curing materials. They display several significant merits as compared to such more conventional monomers as acrylates or styrenes. For one, they typically demonstrate significantly higher polymerization reactivities than acrylate-type monomers bearing equal functionalities; two, they usually have much improved biological safeties and compatibilities, particularly in terms of odor as well as physiological skin irritation profiles, which would be critical for biomedical applications as well as on-site applications involving human occupants; three, they have robust solubility properties that are often conducive for both solvent-borne as well as water-borne formulations; four, they often feature low viscosities, which is highly desirable for formulating high-solid-content as well as solventless sprayable coats and inks with no or reduced emissions of VOCs (i.e., Volatile Organic Compounds). These technical advantages collectively hold promises for more market growths for acrylamides materials.
Furthermore, it is known to experts skilled in the art that, unlike the preparations of acrylates where direct esterifications are feasible through the reactions of acrylic acids and alcohols precursors, acrylamides can not be prepared in otherwise similar processes from acrylic acids and amines since the latter would inevitably incur so-called Michael addition by-products. There are thus up to date fairly limited disclosures in the literature on the preparation methods for acrylamides. Few know protocols are Japanese patents JP 09-279395, JP 49-66625, JP 05-163279, PCT filing WO 2015/146876, Chinese patent CN103992294, and scholarly articles Tetrahedron Lett. 2003, 44, 7485; Shan Dong Hua Gong, 2015, 44, 33; Ying Yong Hua Gong, 2015, 44, 1257; Can. J. Chem. 1976, 266.
These known disclosures feature either such harsh and operationally challenging conditions as high-temperature thermal cracking technique, or with low production efficiency as well as high capital investments. To date only the Japanese maker, Konjin Chem, has demonstrated commercial production capacities for such hallmark products as 4-acryloylmorpholine (ACMO) and a few other analogs. The Konjin process, however, still employs energy-intensive chemical pyrolysis at temperatures as high as 380° C.
On the other hand, various formamides are widely used as industrial solvents, raw materials, and high-performance electro-chemicals. It is equally notable to people skilled in the art that formamides are not routinely prepared by the direct actions of formic acid and amines (He Cheng Hua Xue, 2014, 22, 250). Some relevant literatures on preparations of these substances are Chinese patents CN 2012104656754, CN 2013105013840, CN 2013104152600, and WO 2016131371A. These protocols teach the uses of corrosive halogenated precursors and expensive metal catalysts.
It is thus transparent to the practitioners in the fields that newly inventive production techniques for acrylamides as well as formamides are highly sought-after in order to meet market demands with better operational safety and efficiency, higher levels of environmental friendliness, and above all lower capital investments and cost. The present invention disclosed for the first time a process that can simultaneously produce both types of substances with the above-defined principles.